Fill 'er Up With Hydrogen

Fill 'er Up With Hydrogen

The methanol processor under Commander II’s hood chugs out enough hydrogen to take the vehicle a shade under 200 kilometers between methanol fillups. The range is limited by the small size of the fuel tank-a consequence of the bulky fuel processor. The big hangup, though, is that the fuel processor takes a half-hour to warm up, which is a half-hour longer than drivers are willing to wait. The problem is that the processor uses steam to free the hydrogen, and getting up a head of steam takes time-just as it did for the steam cars of the early 1900s.

DaimlerChrysler, Ford and Ballard say they are working on a solution: a next-generation fuel processor that uses a catalyst, rather than steam, to kick-start hydrogen production. The new system is much smaller-slightly bigger than a file box-and weighs half as much as the beast squeezed under Commander II’s hood. But this sophisticated little fuel processor has been a long time coming. Ford and DaimlerChrysler both planned to show the technology in demo cars this spring, but only Ford’s appeared on the auto show circuit-and its fuel processor was not functioning. Ford’s Kopf says the two companies decided to pool their resources-including the scarce automotive engineers comfortable with the electric vehicle’s communications systems-to get the processor working in DaimlerChrysler’s next concept car. “The system is so complicated, and it’s got a lot of computers talking to each other,” says Kopf. “There are not a lot of people in the world capable of making these run.”

While these elite engineers fuss over catalysts and controls, doubts are growing over the viability of methanol as a consumer product. Methanol is nasty stuff-not only can it prove fatal if ingested, but even splashing it on the skin can cause blindness and liver and kidney failure. And because methanol dissolves in water, it poses a threat to underground drinking water supplies. That makes oil firms nervous; they are already scrambling to get the methanol-based fuel additive MTBE (methyl tertiary butyl ether) out of their gasoline, after the foul-tasting chemical began showing up in California’s drinking water.

The most obvious solution, of course, is to directly use hydrogen as the fuel. That would eliminate the need for a reformer as well as the climate-warming carbon dioxide it generates (though some CO2 would still be released during hydrogen production from fossil fuels, the most common method today). The problem is that while hydrogen packs more energy by weight than any other fuel (about three times more than gasoline), it is hard to stuff much of this energetic gas in a fuel tank. Pack a commercially available compressed gas tank with hydrogen, and it will take your vehicle barely 150 kilometers-no farther than today’s best car batteries. Hydrogen is also the smallest of molecules and slips through the smallest holes-a worrisome trait, given its characteristic flammability. (Remember the Hindenburg?) DaimlerChrysler pushed a demo car 450 kilometers using a liquid hydrogen tank, but the cryogenic technology to store fuel at -253 C (just 20 degrees above absolute zero) is not mature for mass markets. And good luck finding a hydrogen filling station-there are only a half-dozen worldwide.

Hydrogen availability may become less of an issue, though, as major oil companies warm to the challenge of distributing the gas. Graham Batcheler, president of Texaco Energy Systems, the oil giant’s advanced-fuels subsidiary in Houston, says the company believes that the fuel cell will replace the internal combustion engine over the long haul. He considers it inevitable that drivers will be filling up with hydrogen-and he wants them to do it at a Texaco station. Rather than fighting to protect its gasoline franchise, Texaco is investing in the key technology to make hydrogen fueling possible: advanced storage tanks.

One possibility for solving the hydrogen packing problem is simply rethinking compression. Stronger tanks could compress the hydrogen to greater pressures, or radically redesigned vehicle frames could accommodate massive but oddly shaped tanks. Another option is to pack tanks full of materials that bind hydrogen, slowing down the molecules without liquefying the gas. Graphite fibers with intricate nanostructures, for example, have been shown to absorb more than 20 percent hydrogen by weight, allowing far more of the gas to be stuffed into a tank.